1. Field of the Invention
This invention relates to electrical connectors and, more particularly, is directed towards a contact terminal for use in combination with a modular telephone-style plug.
2. Description of Related Art
Telephone-style modular plugs and jacks are well-known. They are used quite extensively in the telephone and communications industries, and for general interconnect purposes.
The modular plugs of the prior art typically utilize a plurality of side-by-side, substantially planar contact terminals to terminate a corresponding plurality of insulated wires.
A typical prior art contact terminal for such a modular plug is indicated generally by reference numeral 10 in FIG. 1. Contact terminal 10 (also referred to as a contact blade or contact pin) typically includes an upper body portion 11, a middle body portion 12 and a lower body portion 13. Each of the body portions 11, 12 and 13 include a central portion, located generally where the reference numerals 11, 12 and 13 are placed on FIG. 1. Typical contact terminals of the prior art are also described, for example, in U.S. Pat. Nos. 4,412,715 and 4,874,330, both of which are specifically incorporated herein by reference.
Still with reference to FIG. 1, the contact terminal 10 of the prior art is characterized by a pair of shoulders 14 and 16 which extend laterally from both sides of upper body portion 11. The purpose of shoulders 14 and 16 are to firmly seat the contact terminal 10 in a contact-receiving slot of the plug (not shown).
Upper body portion 11 also typically includes an upper, linear surface 18 for mating with a spring contact portion of the mating modular jack (not shown). Modular jacks which include conductors having spring contact portions are taught, for example, in U.S. Pat. Nos. 4,717,217 and 4,738,638, the disclosures of which are specifically incorporated herein by reference.
It may be appreciated that middle body portion 12 has a reduced width compared with upper and lower body portions 11 and 13.
Extending downwardly from lower body portion 13 are typically a pair of insulation-piercing tangs 20 and 22 which are adapted to pierce the insulation of an insulated wire (not shown) placed in the modular plug. An arch 28 is formed between tangs 20 and 22.
Still with reference to the prior art contact terminal 10 of FIG. 1, extending laterally at the approximate junction between middle and lower body portions 12 and 13 are a pair of teeth 24 which are designed to become embedded during installation in a terminal receiving slot (not shown) in the modular plug, all of which is very conventional. Teeth 24 therefore help maintain contact terminal 10 in place in the modular plug. An additional pair of teeth 26 are also provided in lower body portion 13.
Although the contact terminal 10 of the prior art generally functions quite well, as signal speeds increase on communication lines, the problem of unwanted cross-talk also increases. Data rates, for example, can go up to 50-200 mb per second. Cross-talk can be a significant problem at these data rates, and it would therefore be highly desirable if some mechanism were provided for minimizing such cross-talk.
In addition, it may be appreciated from FIG. 1 that the path of the signal from the input side (upper surface 18) down through the middle portion 12 and to the pair of tangs 20 and 22 is non-uniform. That is, the signal encounters a large mass at the upper body portion 11, a thinner but still substantial mass through the middle body portion 12, and splits at the arch 28 of lower body portion 13 into two portions finally being fed via tangs 20 and 22 into the insulated conductors (not shown) therebelow. Such non-uniform signal paths may contribute to undesirable reflections of the signal. It would be highly desirable if a way were found to reduce the likelihood of such undesirable reflections (thereby improving the VSWR) by providing a more uniform signal path.
Finally, the prior art contact terminal, although constructed of phosphor-bronze, must nevertheless be gold plated in order to provide sufficient reliability and contact integrity prior to installation in the plug. Since gold is a very expensive material, it would be highly desirable to provide ways for minimizing the quantity required.